---
typeId: req
recordId: benac-pkg-005
fields:
  title: Package interfaces
  statement: >-
    A package shall declare one or more package interfaces.

    A package interface shall identify how the Station talks to the package and how the
    package talks back.

    Each package interface declaration shall identify the interface identifier, request
    schema reference, descriptor config schema reference where relevant, output schema
    reference where relevant, declared capabilities by operation phase, artifact
    requirements, resource requirements, evidence behavior, effect behavior, and
    diagnostic behavior where relevant.

    A package interface shall describe the contract for invoking that interface.

    A package interface shall not grant capability authority.

    A package interface shall not classify the package.

    A package interface shall not classify how package work is performed.

    A package interface shall not rely on names, labels, filenames, provider names,
    product names, model names, repository names, URLs, or human-readable descriptions
    as authority.

    Invocation shall resolve the package interface before request validation, descriptor
    config validation, capability review, artifact availability review, resource review,
    evidence recording, effect recording, or output validation.
  rationale: >-
    Interfaces are the package's public conversation surface. They define request shape,
    configuration shape, output shape, requested authority, required artifacts,
    resources, evidence, and effects without exposing or classifying package internals.
  verification: >-
    Interface declaration controls compatible invocation requests. A package with
    calculator and formatter interfaces validates and invokes each interface under the
    correct request, config, and output schemas. A request valid for one interface fails
    under the wrong interface.
  testable: true
  status: draft
  area: BENAC-PKG
  sourceDocument: user-requested schema-first requirements cleanup
  sourceVersion: 2026-05-06
  sourceSections:
    - Package model, descriptors, and package claims
  order: 79
---
